Answer:Species Dynamics. This theory is quite straightforward: species that can colonize new areas faster and reproduce in greater number than they become extinct have the greatest chances to thrive. The tropics offer favorable conditions for these conditions to be met.
There Is More Diversity Near the Equator. ... Another argues that more solar energy is received around the equator, allowing for greater species richness. A third points out that equatorial tropics are the largest biome, so it makes sense that there would be more species.
When a molecule moves down its concentration gradient is it participating in passive transport; moving up the concentration gradient requires energy making it Answer:active transport